Process of forming refrigerator elements



April 23, 1929. MUFFLY s O)? REFRIGERATOR ELEMENTS Filed July 1, 2Sheets-Sheet 2 WWW'W w Patented Apr. 23, 1929.

UNITED STATES "GLENN MUFFLY, OF DETROIT, MICHIGAN, ASSIGNOR TO COPELANDA CORPORATION OF MICHIGAN.

PATENT OFFICE.

PRODUCTS, INC.,

PROCESS OF FORMING REFRIGERATOR ELEMENTS.

Application filed July 1, 1927. Serial No. 202,789.

This invention relates to the process of forming chambers such as areused for the expansion chambers of refrigerating systems, and theprincipal object is to provide a simple and economical process offorming the -same.

Another object is to provide a process of forming chambers from sheetmetal, such chambers having a relatively large area of small depth andanchored against deformation at a plurality of points dver the areathereof.

Another object is to provide a method of forming chambers from sheetmetal comprising in securing a pair of matched sheet metal memberstogether along their edges and holding the same together at a pluralityof spaced points between their edges, introducing fluid under pressurebetween said plates whereby to separate the same at all points exceptthe edges and the forementioned spaced points and thereafter securingsaid members togcther at said spaced points.

A further object is to provide a method for forming a chamber from sheetmetal comprising in securing two fiat sheet metal plates together inmatching relationship by welding the same together along their edges,bending the sheets into a generally ring shaped form, placing the sheetswithin a die having a surface cooperating with the outer of the sheetsand formed to provide portions in contact with the edges and with aplurality of spaced points intermediate the edges, the die also providcdwith a portion in contact with substantially the full area of the innerof the plates, introducing fluid under pressure between the plateswhereby to exp-and the same at all points except the edges and theforementioned spaced points, and thereafter removing and welding theplates together at said spaced points.

The above being among the objects of the present invention the sameconsists in certain steps of operation to be hereinafter described wit-hreference to the accompanying drawings, and then claimed, having theabove and other objects in view.

In the accompanying drawings which illustrate a suitable embodiment inthe present invention and in which like numerals refer to like partsthroughout the several views,

Fig. l is a side elevation of a completed expansion chamber for arefrigerating mechanism formed in accordance with the present invention.

. Fig. 2 is a side elevation of the expansion chamber shown-in Fig. 1. Y

Fig. 3 is a sectional view talen on the line 33 Fig. 1.

Fig. 4 is a plan View of the plates employed in the present inventionsuperimposed and welded together alon their edges.

Fig. 5 is an edge view of the plates shown in Fig. 4;.

Fig. 6 is an edge view of the plates shown in Figs. 4 and 5,'after theyhave been bent to a generally ring shaped section.

Fig. 7 is a sectional view taken longitudinally through a dieconstructed in accordance with the present invention in which the platesas formed in Fig. 6 are shown positioned.

Fig. 8 is a sectional view taken on the line 8-8 of Fig. 7.,

Fig. 9 is a fragmentary sectional view taken on the line .88 Fig. 7,illustratingthe form identical shape and contour by welding or otherwisesecuring the same together throughout their edges in substantially fullycontacting relationship throughout their area, and thereafter holdingthe plates together in contacting relationship at a plurality of spacedpoints between the edges and then introducing fluid under sufficientpressure between the plates to cause the same to be separated at allpoints except the edges and the forementioned spaced points therebyforming a chamber between the plates, the points where the plateschambers from sheet metal, and

of chamber formed from thesheet metal inaccordance with the present.invention, the generally ring Shaped section shown being illustratedbecause i of the convenience with which it may be used in arefrigerating sys tem. It will also be understood that the p-rocess isnot. limited to the formation of such chambers-used exclusively in refrgerating systems, but the chambers formed in accord- I ance with thepresent invention which may be employed for any use-to which they may be1 found acceptable.

an illustration of the use of the presentinvention in forming therefrigerator expansion chamber illustrated in Figs. 1, 2 and 3, Iillustrate the first steps in Figs; 4 and 5.

As shown the rectangular plates of-fiat sheet metal 15 and 16 are placedone over the other in contacting relationship. -Each plate is providedwith an opening such as 17 through the same adjacent one end, and eachopening is preferably provided with a'bossed. portion such as 18 and 19,respectively, about the same. The plates15 and 16 are placed togetherwith the openings 17 at opposite ends from each other andwiththe bosses18 and 19011 the sides opposite the contacting faces of plates. Theplates are then secured together over the-length of their entire edges'so as to seal such edges. This may be done by welding, rolling the edgesor by other means, but Lhave found that line welding by the electricalprocess is the most satisfactory, quickest and cheapest. After theplates have been secured together, as described, they are bent to theshape shown in Fig. 6, which for the purpose of illustration may betermed a generally ring shaped section, the ri ht hand end of the plate,as viewed in the drawings being bent at right angles to the plane ofsuch end to form a marginal flange such as 20 which is brought intocontact with the outer face of the upper plate 15 immediately inwardlyof the boss 18. The plates bent as indicated in Fig. 6, are then placedin a die of formation illustrated in Figs. 7, 8 and 9. This diecomprises outer sections 2 1 and 22 and an inner section 29. The outersections 21 and 22 are split diagonally'of the plates in end view andare formed interiorly to provide portions 23 contacting against theentire edge portions of the plates 15 and 16 and other portions 24contacting against the surface of the outer plate 16 at a plurality ofpoints over the entire surface between the edges and spaced from theouter plate 16 at the exact contour of the inner plate 15 and is.

received therein in contacting relationship 'with the entire surfacethereof. The opening 17 in the boss 18 is plugged and the pipe 25 I isinserted through an opening 26 in the die section 21 and threaded intothe opening in the boss-19. Fluid under pressure, preferably hydraulic,is applied to the pipe 25 and is transmitted to between the plates 15and 16 within the die, the pressure being sufficient to cause the outerplate 16 to be forced away from the inner plate 15 at all points overthe surface thereof except at the portions 23 and 24 which hold theplates in contact at these points, the outer plate being expanded untillimited by the walls of the die sections 21 and 22 intermediate thepoints 23 and 24. This causes a chamber 26 to be formed beseparatedsufiiciently to allow free passage of tween the plates 15 and 16 whichis interthe fluid past the projections 27, but so spaced that theprojections 27 form a maze within the chamber 26 through which the fluidmust pass in its path from one opening 17 to the other. In addition toforming such a maze for the passage of fluid through the chamber 26 theportions 24 of the die form depressions 28 in the, face of the outerplate'which. in-

crease the heat transferring surface of the same.

It will be apparent, of c0urse,'that the portions 24'of the die sections21 and 22 must be formed with suflicient draft to allow the die plate15. After the expansion is completed the pressure is relieved and thesections 21 and 22 separated and the section 29 withdrawn. The platesthus formed are then removed and are. secured together at the bottom ofeach depression at which point they are in contact'by spot-welding orthe like, and the flange 20 is secured to thesurface of plate 15. Bysecuring the plates 15 and 16 together at the bottom of each depression28 the structure is given the ability to withstand relatively highpressures within the chamber 26 without distortion, for if suchintermediate points of securement between the edges were not provided,the pressure in the chamber 26 acting on the entire area of the plates15 and 16, would tend to deform the plates and tear the edges apart. r

It will be recognized that the specific order of steps here describedare not all essential to the successful practice of this process, suchas, for instance, the welding of plates 15 and 16 together beforebeingbent into the generally ring shaped section shown in Fig. 6,

but various modifications ofthe same may I be worked out withoutdeparting from the invention involved, and formal changes may be madeinthe specific embodiment of the invention described without departingfrom the s irit. and substance of the broad invention, t e scope ofwhich is commensurate with the appended claims.

What I claim is: t 1. The method of forming matching sheet metal memberstogether along their edges, holding said members together in contactingrelationship along their edges and at a plurality of spaced pointsbetween their edges, introducing fluid under pressure between saidplates whereby to separate the same at all points except said edges andsaid spaced points, and thereafterv securing said members together-atsaid spaced points.

2. The'met-hod of forming an expansion chamber for refrigeratingsystems, comprising placing two sheets of metal one abovethe other inmatching and contacting relationship, connecting said sheets togetheralong their edges, enclosing said sheets in. a die which clamps theedges of said sheets together one surface of said die being providedtionship by joinin them along their edges,

placing said joine sheets within a die which clamps the edges of saidsheets together and which is provided with a surface cooperating withone of said sheets having certain portions thereof spaced from saidsheet and other portions thereof substantially in contact with saidsheets along the edges thereof and at a plurality of other spacedpoints, introducing fluid under pressure between said plates Y wherebyto separate the same except along said edges and said spaced points, andthen welding said sheets together at said spaced points.

4. I The-method of forming a chamber from sheeti'netal, comprisingsecuring two fiat sheet metal plates together in matching relationshipby welding the same together along their edges, bending said sheets intoa generally ring shaped form, placing said sheets within a die having asurface cooperating with the outer of said sheets formed to provideportions in contact with said edges and with a plurality of spacedpoints intermediate said edges, said die provided with a portion 1ncontact with substantially the full area of the inner of said plates,introducing a fluid chambers fromsheet metal, comprising securing a pairof under pressure between said plates whereby to expand the same exceptat said edges and points, and thereafter removing and welding saidplates together atsaid points.

5. The method of forming a chaniber from sheet metal, comprising placinga pair of generally ring shaped sheet metal members, one

telescoped within the other and secured toget-her throughout theiredges, Within a die comprising aplurality of outer parts contactingagainst the outer of said members along the edges thereof and atfaplurality of spaced points between the edges'and an inner membercontacting against the inner of said members, forcing fluid underpressure between said plates whereby to separate the same atsubstantially all points except sai'd edges and said spaced points,removing said members from said die, and securing said members togetherat said spaced points.-

6. The method of forming a chamber from sheet metal, comprisingproviding a pair of substantially equal sized plates, providing anopening through one of said'plates, placing said plates in superimposedcontacting relationship and welding them together along their edges,bending said plates into a substantially ring shaped section, placingsaid bent plates within a die comprising outer sections contactingagainst the edges of the outer of said plates and at a plurality ofspaced polnts between the edges',-and spaced from'said outer plate atall other points,

and an inner member contacting against the, v

inner surface of the inner of said plates, conmeeting a pipe. with saidopening, forcing fluid under pressure through said pipe to separate saidplates at all points except said edges andsaid spaced points, removingsaid plates from said die, and thereafter securing the ends of saidplates relative to each other spaced points. I a

7. The method of forming a curved chambcr device comprising in providinga pair of flat sheet metal plates, placing said plates in superposed andcontacting relation, sealand spot-welding said plates together at I ingthe edges of one of said plates to the 7 other of said plates, bendingsaid plates to approximate the shape of the desired fin ished product,enclosing said bent platesbetween die members which clamp said sealededges against the other of said-plates and spaced points, at least oneof said die parts being spaced from the adjacent of said members atsubstantially all other points thereon, and thereafter introducing fluidunder pressure between said members whereby to cause "them to beseparated at all points over their surface except at'said edges and saidspaced points. v

-. GLENN MUFFLYF

